In order to study the influence of the aggregate silica-fume modification on the scale effect of cubic compressive strength of recycled concrete，240 recycled concrete cube specimens were conducted under the com? pression tests，taking the water-binder ratio of silica-fume paste，the recycled aggregate replacement ratio and the dimension of specimens as test parameters. The test results show that the improvement of the cubic compressive strength of recycled concrete with silica-fume modification（w/b=1.0）reaches the maximum value，while the reduc? tion in scale effect is also the most significant. The scale effect of cubic compressive strength becomes more obvious with the increase of recycled aggregate replacement ratio，and the scale effect of recycled concrete with the recycled aggregate replacement ratio of 100% is about 1.4 times that of ordinary concrete. Silica-fume modification can re? duce the scale effect of recycled concrete. When the recycled aggregate replacement ratio is 100%，the scale effect of recycled concrete with silica-fume modification is about 19.2% lower than that of recycled concrete without modifica? tion. The calculation equations of scale effect law are proposed，which can be used to analyze the cubic compressive of recycled concrete.